test of href attribute on the math tag
<math xmlns="http://www.w3.org/1998/Math/MathML" href="http://en.wikipedia.org/wiki/Euler%27s_identity"> <mrow> <mrow> <msup> <mi>ⅇ</mi> <mrow> <mi>ⅈ</mi> <mi>π</mi> </mrow> </msup> <mo>+</mo> <mn>1</mn> </mrow> <mo>=</mo> <mn>0</mn> </mrow> </math>
Author: Design Science, Inc. (D. Doyle, R.Miner)